Antifriction support for show-case doors.



No. 788,597. PATENTED MAY 2, 1905. T. ROBERTSON & E. L. MIDDLEBROOK.

ANTIFRIOTION SUPPORT FOR SHOW CASE DOORS.

APPLICATION FILED AUG. 18, 1904.

W LUMWMQE NlTED STATES Patented May 2, 1905.

PATENT OFFICE.

ANTIFRICTION SUPPORT FOR SHOW-CASE DOORS.

SPECIFICATION forming part of Letters Patent No. 788,597, dated May 2, 1905.

Application filed August 18, 1904. Serial No. 221,181.

.To all whom it may concern:

Be it known that we, THOMAS ROBERTSON and ELMER L. MIDnLnBRooK, citizens of the United States, residing at Minneapolis, in

the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in. Antifriction Supports for Show-Case Doors; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our present invention relates to showcases, and has for its especial object to proyide improved antifrietion supports or bearlugs for the sliding doors of said show-cases.

To the above ends the invention consists of the novel devices and combinations of de vices hereinafter described, and defined in the claims.

The invention is .illustrated in the accompanying drawings, wherein like characters indicate like parts throughout the several views.

Figure 1 is an elevation with some parts broken away, showing a pair of our improved door-supports applied in working position to the sliding doors of the show-case. Fig. 2 is a vertical. section on the line a a of Fig. 1; and Fig. 3 is a detail in side elevation, showing a portion of one of the sliding doors and one of the improved roller-bearing supports removed from working positioii, the said roller-bearing support being sectioned approximately on the line 06* 9c of Fig. 2.

Hitherto sliding doors of show-cascs have been constructed of glass plates provided with wooden supporting-frames, and these doors have been mounted on antifriction ball-bearing devices, which have usually been set into the said wooden frames.

Our invention dispenses with the wooden frames and provides simple and eflicient means for applying the ball-bearing devices to the glass panes or glass doors.

The numeral 1 indicates the bed-plates, numeral 2 the top plate, the numeral 3 the rear upper rim of the case-frame, and the nu moral 4 the sliding doors of the show-case.

The doors at their upper edges work in a channel 5, formed in the rim 3, and are spaced apart at their upper edges by an in.- terposed strip 6, set into the said rim 3. Just below each door 4- and extending parallel therewith are guide-rails 7, which guide-rails are shown as set into the base 1.

The antil'riction bearing devices support the doors 4; from the rails 7 and involve a twopart or sectional ball-container 8, having an endless ball-runway which is filled with loose bearing-balls 9. The lower portions of the ball-containers 8 are open, so as to straddle the rails 7 and permit the lower ball to rest upon the rails. Hitherto bearing devices of the character so far described have been used; but as applied they have been countersunk into the wooden frame of the door supported thereby. In accordance with our invention, however, these ball-containers 8 are provided with vertically-projecting side plates or flanges 10, that are adapted to embrace the sides of the glass door 4, which they support. The doors 4; are preferably notched out or cut away approximately, as shown at 4 in Fig. 3, to form a seat which is adapted to receive the body portion of the ball-container S.

It is a wcll-kilown fact that metal and g] ass under varying temperatures will expand and contract at different ratios. This has made it impossible to properly secure metal of the ball-bearing devices and the glass of the door directly by the use of adhesive material. Hence in accordance with one feature of our invention we interpose plates or strips 11 of tough yielding material, such. as rubher, and secure the same to the glass door and to the metallic plates 10 of the roller bearing devices by cement having the required adhesive properties. In this way the ball-bearing devices are securely attached to the glass doors, and at the same time the different relative expansions of the metallic and glass parts are permitted by the interposed yielding strips 1.1. Furthermore, the said strips 1 1 act as cushions to relieve the glass doors from jars or strains.

Broadly, the combination, with a pane of glass and a support therefor, of a yielding strip interposed between them and united therewith by an adhesive material we do not herein claim, since the same is set forth and broadly claimed in our prior application, Serial No. 186,064, filed December 21, 1903, and allowed April 29, 1904, entitled Means for attaching glass panes to their frames.

The device described, it will be understood, is capable of modification within the scope of our invention as herein set forth and claimed.

What we claim, and desire to secure by Letters Patent of the United States, is as follows:

1. The combination with a glass pane or section, and a support therefor having plates or flanges which embrace the sides thereof,

of yielding strips interposed between said pane and the embracing-flanges of said support, and united to both thereof by adhesive material.

2. The combination with a slidable glass door, of a ball-bearing support therefor having side plates or flan es embracing the sides of said pane, and yiedding strips interposed between said pane and the flanges of sald support, and united to said pane and to said flanges by adhesive material, substantially as described. I

3. The combination with a slidable glass door 4, notched at 4 of the ball-bearing device consisting of the ball-container 8 and balls 9, said container 8 having the side plates or flanges l0 embracing the sides of said door, said container 8 lying in said notch 4, and yielding strips 11 interposed between said side plates and the sides of said door, and

united to both thereof by adhesive material, I

F. D. MERCHANT. 

